Even though Leopold Wilhelm lacked the canonical qualifications, he was invested, with the help of his father, with a number of prince-bishoprics in order to provide him with an income. Unqualified as he was, he officially only held the title administrator, nevertheless realising the full episcopal revenues, of the prince-bishoprics of Halberstadt (1628-1648), Passau (1625-1662), Breslau (1656-1662), Olmütz (1637-1662) and Strasbourg (1626-1662). In 1635, Pope Urban VIII authorised him to become the prince-archbishop of Bremen, but due to its occupation by the Swedes he never gained de facto power.

He returned to Vienna after the situation in the Spanish Netherlands had deteriorated in 1656. In Vienna he was initially occupied with the administration of his various bishoprics, the Teutonic Order which he led as Grand Master and the family affairs of the imperial house. After the death of his elder brother Emperor Ferdinand III, several electors put him forward for the position of Emperor. However, he stalled to allow his nephew to reach the statutory age to ascend the imperial throne, which his nephew did as Leopold I on 22 July 1658 at the age of 18 years. After devoting himself to the affairs of state, Leopold Wilhelm retired in his final years and lived exclusively for the love of art.[1]

He died in Vienna in 1662.

Patron of the arts

When he assumed the government of the Spanish Netherlands, Leopold Wilhelm, being a great lover of art, employed several painters from the AntwerpGuild of Saint Luke, including the great Flemish painter David Teniers the Younger, who he not only employed as a painter but as keeper of the collection of pictures he was then forming. With the rank and title of "ayuda de camara," Teniers took up his abode in Brussels shortly after 1647.